[all-commits] [llvm/llvm-project] 74af57: Reapply "[VPlan] Compute cost of more replicating ...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 74af5784a570914271a258618bf6f7cb06c50241
      https://github.com/llvm/llvm-project/commit/74af5784a570914271a258618bf6f7cb06c50241
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2025-10-06 (Mon, 06 Oct 2025)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/lib/Transforms/Vectorize/VPlan.cpp
    M llvm/lib/Transforms/Vectorize/VPlanHelpers.h
    M llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
    A llvm/test/Transforms/LoopVectorize/ARM/replicating-load-store-costs.ll
    M llvm/test/Transforms/LoopVectorize/X86/replicating-load-store-costs.ll

  Log Message:
  -----------
  Reapply "[VPlan] Compute cost of more replicating loads/stores in ::computeCost. (#160053)" (#162157)

This reverts commit f80c0baf058dbdc5 and 94eade61a02ae5.

Recommit a small fix for targets using prefersVectorizedAddressing.

Original message:
Update VPReplicateRecipe::computeCost to compute costs of more
replicating loads/stores.

There are 2 cases that require extra checks to match the legacy cost
model:
1. If the pointer is based on an induction, the legacy cost model passes
its SCEV to getAddressComputationCost. In those cases, still fall back
to the legacy cost. SCEV computations will be added as follow-up
2. If a load is used as part of an address of another load, the legacy
cost model skips the scalarization overhead. Those cases are currently
handled by a usedByLoadOrStore helper.

Note that getScalarizationOverhead also needs updating, because when the
legacy cost model computes the scalarization overhead, scalars have not
been collected yet, so we can't each for replicating recipes to skip
their cost, except other loads. This again can be further improved by
modeling inserts/extracts explicitly and consistently, and compute costs
for those operations directly where needed.

PR: https://github.com/llvm/llvm-project/pull/160053



To unsubscribe from these emails, change your notification settings at https://github.com/llvm/llvm-project/settings/notifications